export default `
float snow(vec2 uv, float scale) {
  float w = smoothstep(1.,0.,-uv.y*(scale/10.));
  if(w<.1)return 0.;
  uv+=time/scale;
  uv.y+=time*2./scale;
  uv.x+=sin(uv.y+time*.1)/scale;
  uv*=scale;
  vec2 s=floor(uv),f=fract(uv),p;
  float k=3.,d;
  p=.5+.35*sin(11.*fract(sin((s+p+scale)*mat2(7,3,6,5))*5.))-f;
  d=length(p);
  k=min(d,k);
  k=smoothstep(0.,k,sin(f.x+f.y)*0.01);
  return k*w;
}
`
